In a digital automatic train control (ATC) scheme that has recently become mainstream, a control device mounted in a railroad vehicle generates a brake pattern based on a gradient or a performance of the railroad vehicle. For this reason, gradient information needs to be provided to (stored in) the control device of the railroad vehicle in advance.
Here, tracks are not necessarily constructed according to drawings. For this reason, after tracks are completely constructed, it is necessary to actually measure a gradient and provide an actual measurement value to the control device as gradient information.
In connection with actual measurement of the gradient, a device for detecting and inspecting maintenance facility data disclosed in Patent Literature 1 includes an irradiating device and a light receiving device which are attached to roofs of front and rear vehicles in the composition of an inspection car in which a plurality of vehicles are connected. Further, directions of the devices are automatically changed so that light from the irradiating device is consistently received by the light receiving device, a curvature radius and a gradient amount are calculated based on a shift amount obtained by measuring a change angle from the positions of the irradiating device and the light receiving device when the vehicle composition of the inspection car in which a plurality of vehicles are connected is arranged along a horizontal straight line, and track maintenance facility data including curved line information and gradient information of a route shape is detected.
Then, as the inspection car travels, track maintenance facility data including bifurcation information as well as curved line information can be acquired, and thus time and effort taken to measure bifurcation information are saved. In addition, by comparison with obtained data, previous track maintenance facility data can be inspected, and thus reliability of data can be improved, and a problem can be detected early.